feat: Configurable colors for card counter

This patch adds support for:

 - User-defined colors for card counters;
 - 3 additional types of card counters.

The colors used for counters is stored locally and not shared with other
users. This is intentional as the feature is likely to be used for
improved accessibility.

In order to preserve backwards-compatibility, and because I don't have a
better idea, counters keep their existing color-based names (Red, Green,
Yellow) in menus and in the message log. For consistency, the new
counters also get assigned color-based names (Cyan, Purple, Magenta).

This choice is a compromise, as allowing user-defined names for counters
raises many additional (UI/UX) questions that I don't know how to
answer. A good long-term solution would be to include counter names as
part of a game definition system and hence would be in scope for #1740.

The choice of adding 3 additional types of counters and the Cyan, Purple
and Magenta names are not random. The existing code for determining
counter colors goes: Red, Green, Yellow, Cyan, Purple, Magenta, Black
(unreadable) and thus 6 is the maximum number of counters that existing
versions of Cockatrice are able to support. This way, released clients
get a degraded experience (cannot interact with the new counters,
messages in the server log say "Player X places 1 on Card (now 1)"
without specifying 1 of what), but do see the counters properly.

Fixes #2020

oracle/CMakeLists.txt

@@ -28,6 +28,7 @@ set(oracle_SOURCES
     ../cockatrice/src/game/cards/card_database_parser/cockatrice_xml_4.cpp
     ../cockatrice/src/settings/cache_settings.cpp
     ../cockatrice/src/settings/shortcuts_settings.cpp
+    ../cockatrice/src/settings/card_counter_settings.cpp
     ../cockatrice/src/settings/card_database_settings.cpp
     ../cockatrice/src/settings/servers_settings.cpp
     ../cockatrice/src/settings/settings_manager.cpp